The head of the UN population agency said that the world must address why 8.7 million young women aged 15 to 24 resort to unsafe abortions each year.

Babatunde Osotimehin also called on governments to explore why more than 200 million women in developing countries who want to prevent pregnancies don’t have access to contraception. And he said countries must answer why one in three girls in developing countries are married before they turn 18, despite near universal commitment to ending child marriages.

He spoke at the opening session of a week-long meeting of the UN Commission on Population and Development to review progress and tackle new challenges since the landmark UN population conference in Cairo in 1994.

The Cairo conference changed the UN Population Fund’s focus from numerical targets to promoting choices for individual women and men, and supporting economic development and education for girls. Underlying the shift was research showing that educated women have smaller families.

The conference broke the taboo on discussing sexuality,adolescent sexual behavior and the real concerns of women and families.

At the heart of the action plan that 179 countries adopted in Cairo is a demand for equality of women through education,access to modern birth control, and a recognition that women have the right to control their reproductive and sexual health and choose if and when to become pregnant.

The only reservation added at the conference was that this should be in accordance with national laws, religion and culture.

Osotimehin told the opening session that in the 20 years since Cairo there have been “great gains” in reducing poverty, improving girls’ education, reducing maternal and child mortality, and providing access to sexual and reproductive health services, including family planning, and protecting reproductive rights.

But he said “discriminatory laws, practices and attitudes continue to keep women and young people, particularly adolescent girls, from accessing sexual and reproductive health services.”

Osotemehin, the Population Fund’s executive director, said this means it’s okay for girls to marry, have sex and have children, but they’re not old enough to have access to contraception and sex education, or to control their own bodies.